Spool for fibre optic media

Abstract: A spool (10) for filamentary material such as optical fibers and others consists of two members (20, 22) which are locked together to form a drum with two opposed flanges (14, 16) defining a winding space. The two members (20, 22) may be separated to allow material wound on the drum to be removed at will. After the material is removed, the two parts may be locked again making the spool reusable.

Description: This invention pertains to a spool for holding wires, cables or optical fibers, and more specifically to a spool which can be separated at will into two parts. Filamentary materials such as wires, cables, optical fibers, are kept for ease of handling on a spool consisting of a tubular drum having two opposed ends and two flanges affixed to said barrel at the respective ends and extending radially outwardly therefrom. One end of the elongated material is secured on the drum and the elongated material is then wound thereon. Once the spool has been transported to the cabling site, the material is paid off from the spool until a preselected length has been reached. A problem with existing spools relates to the manner in which remainders are removed. The elongated material is provided in various lengths which normally exceed the amount of material actually required. For example, while a spool may hold 110km of optical fiber, of which only a 100km of optical fiber may be actually required. After a desired amount of material, for example about 100km, is removed from the spool the remainder (i.e. about 10km) is usually too short for most applications and must be discarded. However, this remainder must still be removed from the spool if the spool is to be reused. In prior art spools, the remainders could be removed by paying it off the spool, a very time consuming operation. Moreover, this was also unsatisfactory because it may require equipment which may be used more efficiently elsewhere, and results in a length of unwound material which is difficult to handle. More frequently the remainder was simply cut off, however it was almost impossible to cut each strand or coil without damaging the barrel, especially if a relatively thin material is involved, such as an optical fiber. US-A-4 387 863 discloses a two-piece spool formed by intermeshing two identical semi-circular segments and provided with an outer channel defined by flanges for holding a cable connector. FR-A-2 204 188 discloses a spool constructed in accordance with the preamble of claim 1. The spool is held together by integral bayonet means. An objective of the present invention is to provide a spool for winding filamentary material, wherein said spool is separable into two pieces to permit the removal of remainders from the spool. Another objective is to provide a spool made of two pieces, said pieces being identical for ease of replacement. A further objective is to provide a spool which may be made by a single cavity injection molding. Other objectives and advantages of the invention shall become apparent from the following description. In accordance with the present invention, there is provided a spool comprising a first member and a second member, each of said members comprising a cylindrical wall, an inner end wall provided with an edge, and an outer flange, and interlocking means provided on said inner end walls for selectively interlocking said members to define a winding space for holding filamentary material, said interlocking means being capable of being selectively released to disengage said members and allow at least a portion of said material to be removed therefrom, characterized in that said interlocking means are removable plugs, each provided with a camming surface arranged, when each plug is turned, to bear against said edge for urging said members towards each other. The spool is preferably made of two identical members. The flanges may be tapered or perpendicular to the barrel. A resilient sleeve may be mounted on the drum for the protection of the wound material. A number of preferred embodiments constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows an exploded side sectional view of a first embodiment of the present invention; Figure 2 shows a partial end view taken along line 2-2 in Figure 1; Figure 3 shows another partial end view taken along line 3-3 in Figure 1; Figure 4 shows a side-sectional view of the embodiment of Figure 1 once assembled; Figure 5 shows a side sectional view of a second embodiment of the present invention; Figure 6 shows an end view of the embodiment of Figure 5; Figure 7 shows a sectional view of a plug used in the embodiments of Figures 1-6, taken along line 7-7 in Figure 1; and, Figure 8 shows a further spool constructed in accordance with the invention. Figures 1-4 show a first embodiment constructed according to the present invention, in which a spool for filamentary material, particularly optical fibers, consists of a drum and two flanges disposed at the axial ends of the drum to define a cylindrical winding space for said material. Referring to Figure 1, there is shown a spool 310 which is formed of two cup shaped members 312, 314, two caps 316, 318 for closing the cup shaped members, and a plurality of plugs such as plugs 320 and 322 for securing the cup shaped members 312, 314 to each other. Cup shaped member 312 is formed of a disk-shaped wall 324 extending radially and having two annular lips 326, 328 extending axially to define an annular space 330. Wall 324 is reinforced with ribs 325 (seen also in Figure 6) which may be slanted radially inwardly as at 327 to permit a fiber to be wound on lip 328 as discussed in more detail below. Wall 324 extends radially away from a cylindrical wall 332. A circular plate 334 extends radially inwardly of the other end of wall 332. Wall 332 has an outer cylindrical surface 336. Of course, it should be understood that walls 324, 332 and plate 334 are made simultaneously as an integral member. Plate 334 is formed with a central cylindrical hub 338 and a plurality of holes disposed around hub 338 including a first hole 340 and a second hole 342. Hole 340 is defined by an oval shoulder 344, as shown in Figure 2. Preferably the edge 346 of shoulder 344 is not parallel to plate 334, but rather is slanted, as shown in Figure 1. Hole 342 is defined by an annular shoulder 350. Shoulder 350 is formed with an internal depression 352 having at one peripheral end a stop 354. Opposite hub 338, plate 334 is formed with a circular depression 356. Cap 316 is formed of a circular plate 360 having a peripheral annular wall 362 and a central hub 364, both of which extend axially. Hub 364 has a narrowed portion 367. A plurality of holes 366 are formed on plate 360 matching the location of holes 340, 342. Cap 318 has the same shape as cap 316. Cup shaped member 314 has the same general shape as cup shaped member 312 including disk shaped wall 324', space 330', cylindrical wall 332', plate 336', hub 338', holes 340', 342' and walls 344', 350'. One minor difference is that plate 336' has an annular rib 358' to match depression 356. Plugs 320 and 322 are identical. Each is composed of two cylindrical portions 370 and 372 extending axially with respect to each other. Portion 370 is provided at its free end with an enlarged radial shoulder 374. Shoulder 374 is provided with a wedged shaped knob 371 best seen in Figure 1 on plug 322. Portion 370 is also formed with a hexagonal hole 376, seen more clearly in Figure 6. Portion 372 has an outer cylindrical wall 378 which is smaller than the wall of portion 370. On this wall 378 there are a set of flexible fingers 382. These fingers extend at an angle with respect to the axis of the plug toward portion 370, as best seen in Figure 1. Axially outwardly of these fingers 382, portion 372 is provided with two T-shaped bosses 384. These bosses 384 have a camming surface 386. Preferably portion 372 is pointed as at 390 so that it is easier to insert into holes 340, 342 as discussed in more detail below. The spool 310 is assembled by inserting cap 316 into cup shaped member 312 so that annular wall 362 fits radially inwardly of lip 328 and portion 367 fits into hub 338, as shown in Figure 4. Cap 318 is fit similarly into cup-shaped member 314. In this manner, two substantially identical spool halves 310', 310" are formed (as identified in Figure 4). The two spool halves are then secured to each other by using plugs 320, 322. More specifically, the two spool halves 310', 310" are positioned so that circular holes 342 on half 310' is positioned opposite oval hole 340' on half 310", and vice versa. Prior to securing the two halves together, a plug 320 is inserted through hole 366 of the cap 316 into circular hole 342 until its shoulder 374 abuts wall 350. As the plug is inserted into hole 342, its fingers 382 are bent radially inwardly by the inner surface of wall 350. The plug 320 is dimensioned so that when shoulder 374 reaches wall 350, fingers 382 are past the hole 342 so that they snap outwardly to engage an edge of hole 342 as shown in Figure 4. As a result, the plug 320 is captured by spool half 310'. Identical plug 322 is similarly captured by spool half 310". After the two halves 310', 310" are positioned so that holes 340 oppose holes 342', as described above, they are advanced axially towards each other until plug 320 is fully seated in oval hole 340' with the T-shaped bosses 384 passing through the narrow ends of hole 340'. In this position, knob 371 is disposed in depression 352 of wall 350. Similarly plug 322 is fully seated in hole 340. Other plugs may be inserted between the halves as well, if desired. The plugs are then rotated clockwise, for example, by using an allen wrench in hexagonal holes 376 (c.f. Figure 6). The plugs can be rotated until knob 371 snaps over stop 354 in depression 352. As each plug is turned, camming surfaces 386 on bosses 384 ride on the edge 346 of walls 344, thereby pressing the spool halves 310', 310" together. Turning the plugs the other way unlocks the spool halves. In the embodiment of Figures 1-4, the two cup shaped members 312, 314 are made to be substantially the same, except as noted. The embodiment shown in Figures 5 and 6 is identical to the embodiment of Figures 1-4 except that the cup shaped member 312' is provided only with oval holes 340 and cup shaped member 314' is provided only with circular holes 342. In this embodiment, plugs 320, 322 are inserted through the same cap 318 while in the previous embodiment plug 320 is inserted through cap 316, while plug 322 is inserted from the other side of the spool through cap 318. The embodiments of Figures 1-7 are used in the following manner. After the two spool halves are secured to each other, with a resilient sleeve 391 disposed thereon for protection, as shown in Figure 5, an optical fiber or other filamentary material is wound on the sleeve. The beginning or end of the filamentary material can be threaded through a hole 392 in cap 316 (or a similar hole in cap 318, not shown) and wound on lip 328. At least one of the caps such as cap 318 may be formed with an annular lip 394. This lip cooperates with wall 324' and lip 328 to define a u-shaped space to ensure that the fiber on lip 328' does not slip off. The two half spools can be separated at will by disengaging plugs 320, 322. For example, the spool with the wound material may be transported to the cabling site where a predetermined amount of material is removed therefrom. If the remainder left on the spool is unusable, or if the remainder must be removed for any other reason, the two spool members are separated and the remainder is removed in a neat and manageable coil. This remainder coil is discarded or put to other use, while the spool can be reassembled and shipped back to a manufacturing facility to be reused. Figure 8 shows a further example of a spool 10 constructed in accordance with this invention. The spool 10 consists of a cylindrical drum 12 and two frustoconical flanges 14,16 disposed coaxially with the drum 12 as shown. The drum 12 may be optionally covered with a sleeve 18 made of a resilient material such as a polyethylene foam. This material is commercially available in various sizes which can be cut to a rectangular sheet and its ends can be joined by solvent welding or other means to form the sleeve commercially. The spool is made of a high impact plastics material such as polystyrene or ABS, preferably by injection molding using a single cavity injection mold. The present invention has certain preferred features which are particularly advantageous, especially for optical fibers. Preferably the spool 10 is made of a plastics material which has a thermal expansion coefficient usually larger than the coefficient of some of the material to be wound i.e., the coefficient of optical fibers. Therefore if the material is wound directly onto the drums, a rise in the ambient temperature causes the spool body to expand more than the material wound thereon which in turn may damage the optical fiber by changing its index of refraction. The sleeve 18 being resilient absorbs the expansion of the drum thereby preventing damage to the material. In addition, the sleeve cushions the wound material from shocks and vibrations. Finally, the sleeve prevents the material from sliding on the drum as it is being wound or transported. The sleeve 18 is made of a relatively inexpensive material so that if it is damaged, it is easily replaced. Of course for some filamentary material the sleeve may be omitted. Similarly, since the two spool members are identical, they can be easily manufactured from a single cavity molding and if one is damaged, it is readily replaceable. Obviously, numerous modifications can be made to this invention without departing from its scope as defined in the appended claims.

Claims: A spool (310) comprising a first member (312) and a second member (314), each of said members comprising a cylindrical wall (332,332'), an inner end wall (334,336') provided with an edge (346,346'), and an outer flange (324,324'), and interlocking means (320,322) provided on said inner end walls (334,336') for selectively interlocking said members to define a winding space for holding filamentary material, said interlocking means (320,322) being capable of being selectively released to disengage said members (312,314) and allow at least a portion of said material to be removed therefrom, characterized in that said interlocking means (320,322) are removable plugs (320,322), each provided with a camming surface (386) arranged, when each plug (320, 322) is turned, to bear against said edge (346,346') for urging said members (312,314) towards each other. A spool as claimed in claim 1, wherein each plug (320,322) is provided with flexible fingers (382) that are arranged to snap outwardly once the plug has been inserted in a hole (342) in one member (312,314) to enable the plug to be retained in said member. A spool as claimed in claim 1 or claim 2, wherein said first and second members (312,314) are substantially identical. A spool as claimed in any one of claims 1 to 3, further including an outer end wall (360) and an inner sleeve (338,338') disposed concentrically within said outer cylindrical wall (332,332'). A spool as claimed in any one of claims 1 to 4, wherein annular flanges (324,324') are disposed at the outer ends of said cylindrical wall (332,332'). A spool as claimed in claim 5, wherein at least one of said members (312,314) is formed with a secondary winding surface (328,328') extending axially away from a corresponding annular flange (324,324'). A spool as claimed in claim 6, wherein said secondary winding surface (328,328') is bounded between said annular flange (324,324') and an auxiliary flange (394) axially spaced from said annular flange. A spool as claimed in claim 7, wherein said annular flange (324,324') is formed with slots connecting said secondary winding surface (328,328') to said winding space. A spool as claimed in any one of claims 1 to 8, wherein a shock absorbing sleeve (391) is mounted on the cylindrical wall (332,332') to protect said filamentary material disposed in said winding space.

Inventors: BOYLES LELAND HUBERT, DESROSIERS VICTOR JOSEPH, FAZIO ROBERT VINCENT, PIERRO STEVEN WILLIAM, PINO SANTO, TREFZGER RONALD TRACY, WILKINSON JAMES RICHARD, BOYLES, LELAND HUBERT, DESROSIERS, VICTOR JOSEPH, FAZIO, ROBERT VINCENT, PIERRO, STEVEN WILLIAM, PINO, SANTO, TREFZGER, RONALD TRACY, WILKINSON, JAMES RICHARD
Applicants: CRELLIN INC, CRELLIN, INC.
Application year: 1994
Main classification: B65H75
IPC codes: B65H75